Drill:
Using the pipes as bats, I have them start trying to hit the golf ball wiffle balls as many times as they can. I vary from tossing it from the side, just behind them, and also from the front.

This can be a very frustrating [tag]baseball drill[/tag] so I like to show them how much they are improving by first tossing a few of the baseball size wiffle balls to let them see how they are striking them and then again after the drill and they can usually see a substantial increase in not just the number of hits, but also how much more centered they are hitting them.